1. Technical Field
The invention relates to a touch-sensitive display device with an integrated mechanical operating part for motor vehicles.
2. Discussion
Devices of the type described above serve for combined display of functions and values of a device as well as simultaneous operation of them. They find application in electrical and electronic devices that in turn are integrated into motor vehicles or facilities. The touch-sensitive device, also designated as a touch screen or touch panel, makes possible registration of movements that are converted into meaningful control commands on one and the same as the display device. To induce the operator to touch the display device at the place provided, normally there appears the image of an operating part which the operator then touches. From this, touch screens allow universal possibilities for usage, easy adaptation to the required tasks and high-level dynamics of the functions provided. Large touch screens are becoming ever more convenient and indispensable; man-machine interfaces capable of adaptation are in demand, to implement ever more inputs and outputs of information.
The touch-sensitive display device includes a display device which usually is designed as a liquid crystal screen (LCD display), and a touch-sensitive element which can be based on various technical systems, usually based on capacitative or resistive surfaces.
In certain instances, the advantage of high-level universality of such touch-sensitive display devices and these flat surfaces ends up as a disadvantage. Primarily this is the case if a purely visually-based operation is not possible, and proper operation must at least partially involve the sense of touch, which is not possible on a flat display. If the device must be operated by people with limited or no vision, the device must be able to operate using only the sense of touch.
Such situations may also arise in motor vehicles, when visual attention is required to be devoted to the traffic situation, and operational manipulations must be carried out on palpable operating parts, with no need after some training or experience to look at them. Automotive technology generally requires special operating elements that are haptic and unrelated to sight to minimize visual requirements of devices. Especially important in this regard are shapes that allows the setting of the operating part to be perceived and provide perceptible feedback.
Operation by visually impaired persons of an elevator control unit was the problem that was to be solved in EP 1 598 298 A1 (U.S. Pat. No. 7,404,471). The problem was solved by equipping the touch-sensitive display device present on the on the elevator with one or more push buttons, which are attached to the surface of the display device and can also later be retrofitted. The operating parts are welded, glued, screwed or snapped onto the touch-sensitive display device. The also can be mounted on an adapter and prepared in grouping for attachment to the touch-sensitive display device on the elevator. A touch by the operator on the button is detected as a disturbance in an electromagnetic field, generated in the background of the touch-sensitive display device.
Touch-sensitive display devices also are used as an operating part or input device in motor vehicles. However, to operate the touch-sensitive display, the operator of the vehicle must look at the display device, which may during the operation of the vehicle involve reduced attention to the traffic situation. Therefore, the haptic operating possibility is advantageous, which, however, presupposes a relief shaping of the user surface or some other operating possibilities involving gripping or touching, not currently available on touch-sensitive displays.
U.S. 2004/0201578 A1 offers a solution for this that is designed in such a way that a covering is mounted over a touch-sensitive display device. This covering covers the screen fully or in part, is permanently installed, and is configured to be moved or detached. The covering accommodates an optional keyboard with buttons that can safely pushed without eye contact after appropriate experience in operation of the applicable device. The function is based on mechanical pressure being triggered by the operator and taken up the key, then acting on the touch-sensitive display device and triggering the appropriate control command. The corresponding reaction appears on the touch-sensitive display device, the touch screen, with only a section, a window, used for display. The type of cover is recognized and the incoming movements are correspondingly interpreted. In a further embodiment, the cover has holes by which, as a guide for the operating finger, the touch-sensitive display device is operated. The key assignments are variable and individually programmable, whereby in one embodiment, see-through keys are used in which the designation or a special color generated on the screen, shines through. Also, two or more keyboards can be placed on one screen.
With the arrangement from the above-named text, at the same time the requirement for a small footprint is met, which often represents an important goal when using touch-sensitive display devices. However, one disadvantage of this solution is that only the center position is specified if two buttons are pressed at the same time. Thus, the desired control command can be misinterpreted, if another button is in this center position.
The solutions provided make possible triggering of discrete switching states. However, what is a disadvantage in all known solutions is that no ranges of values can be gone through or analogous values set, and in addition, this setting cannot be done on a mechanical operating part at an unchanging location that the experienced operator can always safely reach. This requirement is especially fulflled by rotatable operating parts.
It is true that the customary mechanical, and especially rotatable, operating parts need spaces enlarged in depth. Such installation depth can no longer be assured according to today's requirements, for example in automotive engineering. Therefore, use of touch-sensitive display devices offers the optimal state-of-the-art solution. As emphasized by their disadvantages, as described above, in terms of operability in moving motor vehicles, only pushbuttons or sliders are used as mechanical operating parts, as documented by the above material.
Therefore, the task that is the basis of the invention is to further develop a device according to the preamble of the invention that implements the haptic operation of mechanical operating parts in motor vehicles with minimum space required, and they are integrated into a touch-sensitive display device.